Everyone of us has its own definition of a good exchange; and it depends on what they are looking for and their own preferences. For me, a good exchange is the one that cares about its users, always has good projects, and has low trading fees. Isn't this what we all want? I found all of this when I started using ProBit Exchange.
you are right but the security is still the main thing...
for me a good exchange can maintain the trust of its users, cheap fees are useless if the exchange is only profit-oriented and not user-friendly/safety.